<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>(</mml:mo><mml:mn>3</mml:mn><mml:mo>+</mml:mo><mml:mn>1</mml:mn><mml:mo>)</mml:mo></mml:mrow></mml:math>-D viscous hydrodynamics at finite net baryon density: Identified particle spectra, anisotropic flows, and flow fluctuations across energies relevant to the beam-energy scan at RHIC
Xiang-Yu Wu, Guang-You Qin, Long-Gang Pang, Xin-Nian Wang
Abstract
To study the bulk properties of quark-gluon plasma produced at beam-energy scan (BES) energies at the Relativistic Heavy Ion Collider (RHIC), we extend the $(3+1)$-dimensional viscous hydrodynamics clvisc to include net baryon number conservation and Israel-Stewart--like equations for baryon diffusion with the neos-bqs equation of state, fluctuating initial conditions from the Monte Carlo Glauber model and the afterburner smash. This integrated framework is shown to provide a good description of identified particle spectra, mean transverse momenta, and anisotropic flows for different centralities and over a wide range of collision energies (7.7--62.4 GeV). It is found that the mean momenta of identified particles and anisotropic flows increase mildly with the collision energy due to larger radial flow. We further compute the multiple-particle cumulant ratio ${v}_{2}{4}/{v}_{2}{2}$ of elliptic flow across BES energies, and find that the relative fluctuations of elliptic flow are insensitive to the collision energy, consistent with the preliminary STAR data. Our model provides a benchmark for understanding the RHIC-BES data and studying the critical properties and phase structure of hot and dense QCD matter.